With summer comes the horseflies

As much as we love to see the sun out, and our horses grazing in the fields there is always that awful sight of horseflies pestering your equine pal.  What are horse flies, and whats out there to stop them?

Horseflieshorseflies - horsefly image

Also written as Horse-flies and in some instances referred to as Gadflies are an absolute pest in the summer months to riders and more so to horses.

All adult flies feed from nectar however it is the female horseflies which bite and extract blood, as the male horsefly does not have a strong enough mouth.  The females require a blood meal before they are able to reproduce effectively.

Horseflies also congregate at a horses eye for moisture, which in turn can cause infections.

The horseflies can transfer blood-borne disease across horses including swamp fever (equine infectious anaemia) fortunately there have been very few cases reported in the UK, however if you do spot the signs of swamp fever you will need to report this.

The signs of swamp fever vary depending on the severity of the condition for more information on swamp fever take a look at this interesting article on Horse and Hound.

Horsefly habitat

Horseflies need warmth, therefore they are seasonal to the UK, their larvae require semi-aquatic habitats, which of course we have in abundance in the UK.

Protecting your horse from horseflies

There are a number of products out there to assist you with helping to repel the flies.  However before you apply any type of repellent you need to get the basics done first.


Make sure your horse is clean of any feaces which will attract the flies.  Keep your stables and fields clean of droppings, you will never be able to stop the flies by doing this, however you may attract more by not carrying out good ‘house keeping’.

horseflies around a horses eyeRugs

Fly sheets are a great way of keeping the flies off, they are generally made from polyester, the mesh is breathable and help prevent the flies from making direct contact.  However as those with horses will know the flies will find openings and will make their way in. Some fly sheets have a repellent within the material to further deter.  Always make sure that you keep the rugs clean, as to not attract the flies, having two sheets means you can rotate them.  Once you have put the sheet on use a repellent to further help the protection.


There are a number of repellents out there, and so far personally I have failed to find one that actually does keep the flies away.  Its worth doing your research and checking out other horse owners reviews.  There are many people making their own with good results.  Make sure that if you have a competing horse that you are not using any prohibited substances, always check the ingredients carefully.


Horseflies tend not to favor shade, so making sure there is a shelter, or shading of some sort in your horses field will again go towards bringing down the numbers pestering your horse.

If you are a horse owner and love everything equestrian then you will probably already be covering everything mentioned. Please do comment on how you deal with horseflies on your horse, what has worked and what has not and share your experience with others.